Allow the user to define ShouldResetNestedFunctions = true to reset nested functions

Author: Atry

reset/src/main/scala/com/thoughtworks/dsl/reset.scala

@@ -53,7 +53,27 @@ import scala.util.control.Exception.Catcher
   * r % 10 should not be r / 10
   * }}}
   */
-object reset {
+trait reset:
+  type ShouldResetNestedFunctions <: Boolean & Singleton
+
+  transparent inline def reify[Value](inline value: Value): Any = ${
+    reset.Macros.reify[ShouldResetNestedFunctions, Value]('value)
+  }
+
+  class *[Functor[_]]() {
+    inline def apply[Value](inline value: Value): Functor[Value] = ${
+      reset.Macros.reset[ShouldResetNestedFunctions, Value, Functor[Value]]('value)
+    }
+  }
+  inline def *[Domain[_]]: *[Domain] = new *[Domain]
+
+  inline def apply[Value](inline value: Value): Value = ${
+    reset.Macros.reset[ShouldResetNestedFunctions, Value, Value]('value)
+  }
+
+object reset extends reset.DefaultOptions {
+  trait DefaultOptions extends reset:
+    type ShouldResetNestedFunctions = false
 
   private class Macros[Q <: Quotes](resetDescendant: Boolean)(using val qctx: Q) {
     import qctx.reflect.{_, given}
@@ -785,32 +805,47 @@ object reset {
   }
 
   object Macros {
-    def reify[V](body: quoted.Expr[_])(using qctx: Quotes, tv: quoted.Type[V]): quoted.Expr[_] = {
-      Macros[qctx.type](resetDescendant = false).reify[V](body/*.underlyingArgument*/)
-    }
-
-    def reset[From, To](body: quoted.Expr[From])(using qctx: Quotes, fromType: quoted.Type[From], toType: quoted.Type[To]): quoted.Expr[To] = {
-      import qctx.reflect.{_, given}
-      val result: quoted.Expr[To] = Macros[qctx.type](resetDescendant = false).reset(body/*.underlyingArgument*/)
-      // report.warning(result.asTerm.show(using qctx.reflect.Printer.TreeStructure))
-      // report.warning(result.asTerm.show)
-      result
+    def reify[ShouldResetNestedFunctions <: Boolean & Singleton, V](
+        body: quoted.Expr[_]
+    )(using
+        qctx: Quotes,
+        translateNestedFunctions: quoted.Type[ShouldResetNestedFunctions],
+        tv: quoted.Type[V]
+    ): quoted.Expr[_] = {
+      import quoted.quotes.reflect.*
+      quoted.Type.valueOfConstant[ShouldResetNestedFunctions] match {
+        case None =>
+          report.error("ShouldResetNestedFunctions is not defined", body)
+          '{ ??? }
+        case Some(translateNestedFunction) =>
+          Macros[qctx.type](resetDescendant =
+            quoted.Type.valueOfConstant[ShouldResetNestedFunctions].get
+          ).reify[V](body /*.underlyingArgument*/ )
+      }
     }
-  }
 
-  transparent inline def reify[Value](inline value: Value): Any = ${
-    Macros.reify[Value]('value)
-  }
-
-  class *[Functor[_]]() {
-    inline def apply[Value](inline value: Value): Functor[Value] = ${
-      Macros.reset[Value, Functor[Value]]('value)
+    def reset[ShouldResetNestedFunctions <: Boolean & Singleton, From, To](
+        body: quoted.Expr[From]
+    )(using
+        qctx: Quotes,
+        translateNestedFunctions: quoted.Type[ShouldResetNestedFunctions],
+        fromType: quoted.Type[From],
+        toType: quoted.Type[To]
+    ): quoted.Expr[To] = {
+      import quoted.quotes.reflect.{_, given}
+      quoted.Type.valueOfConstant[ShouldResetNestedFunctions] match {
+        case None =>
+          report.error("ShouldResetNestedFunctions is not defined", body)
+          '{ ??? }
+        case Some(translateNestedFunction) =>
+          val result = Macros[qctx.type](resetDescendant =
+            quoted.Type.valueOfConstant[ShouldResetNestedFunctions].get
+          ).reset[From, To](body /*.underlyingArgument*/ )
+          // report.warning(result.asTerm.show(using qctx.reflect.Printer.TreeStructure))
+          // report.warning(result.asTerm.show)
+          result
+      }
     }
   }
-  inline def *[Domain[_]]: *[Domain] = new *[Domain]
-
-  inline def apply[Value](inline value: Value): Value = ${
-    Macros.reset[Value, Value]('value)
-  }
 
-}        
+}

reset/src/test/scala/com/thoughtworks/dsl/keywords/ReturnSpec.scala

@@ -46,6 +46,18 @@ object ReturnSpec extends TestSuite {
       assert(result == 42)
     }
 
+    "reset nested function" - {
+      new reset {
+        type ShouldResetNestedFunctions = true
+      }.apply {
+        def continuation = { (!Return(42)): Int!!String }
+        val result = continuation { s =>
+          throw new java.lang.AssertionError(s)
+        }
+        assert(result == 42)
+      }
+    }
+
     "return the right domain" - {
       def continuation: Int !! String = reset[Int !! String]{!Return("right value") }